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Basin-scale runoff changes reflect the comprehensive impact of various environmental variables including climate and vegetation. Among them, vegetation plays an important role in the process of runoff generation and is one of the key links affecting the hydrological cycle. However, the contribution of vegetation to runoff changes is still unclear. In order to analyze the main driving factors of runoff changes in the Yanhe River Basin, this research builds a BPG model based on the Budyko framework, Porporato model, and Guswa model to evaluate the sensitivity coefficient of runoff to vegetation change, and quantitatively reveals the contribution of vegetation to runoff change. The results showed that, the runoff in the Yanhe River Basin decreased significantly from 1982 to 2018, and a mutation point occurred in 1999. After that, the runoff decreased by 29.88% and the NDVI increased by 15.30%. In terms of the sensitivity to runoff changes, runoff is more sensitive to changes in basin characteristics including vegetation than the climate change. According to the concepts of relative contribution and absolute contribution proposed in this research, the relative contribution rate and absolute contribution rate of climate change and basin characteristic changes were − 18.13%, 117.67% and 43.22%, 56.78%, respectively. Changes in basin characteristics such as vegetation, terraces and check dams caused by human activities are the main causes for runoff changes. The relative contribution rate and absolute contribution rate of vegetation change to runoff change were 34.98% and 16.88%, respectively, which is one of the dominant factors for basin characteristics change. And basin characteristic factors such as artificial water withdrawal, terraces and silt dams are the other main contributors to runoff changes. The research results can provide a theoretical basis for guiding future ecological restoration projects and water resources planning in the basin. • BPG model was built to evaluate the sensitivity and quantitatively reveal the contribution of vegetation to runoff change. • Proposed the concepts of relative contribution and absolute contribution of runoff change. • The runoff was more sensitive to basin characteristics change than climate change. • Climate change led to runoff increase while basin characteristics change led to runoff reduction in Yanhe River. • Changes in basin characteristics such as vegetation are the dominant factors of runoff changes. [ABSTRACT FROM AUTHOR]

Highlights • Reviewed the transport characteristics influence the contaminant transport. • Reviewed the empirical and mechanical contaminant transport model. • Coupling the hydrology and contaminant transport models can design VFS precisely. Abstract This work provides a comprehensive review on the specific transport characteristics and the associated transport models of sediments, chemicals, and colloids in vegetative filter strips (VFSs). The main goal of the review is to improve current understanding of the main processes, mechanisms, and models of VFSs as the best management practice to mitigate the non-point source pollution. The overall removal efficiency of a VFS varies among different contaminants. For sediments, particle size and distribution are the critical factors that influence their fate and transport in VFSs. For adsorptive chemicals such as pesticides and phosphorus (P), one critical factor for their fate and transport in a VFS is the distribution coefficient between soluble and particle phases. For non-reactive chemicals such as nitrogen (N), soluble phase plays an important role in controlling their fate and transport in a VFS, while bio-chemical reaction may also be important. For colloids, particle and flow characteristics are the main factors affecting their transport and removal in a VFS. Previous studies have built transport models based on the specific characteristic of contaminants. Some of the models are empirical with regression equations based on experimental data. There are also some mechanistic VFS models that are process-based and rely on contaminant transport mechanisms. When coupled with the hydrology models, these models can be used to simulate the fate and transport of various contaminants in VFSs. [ABSTRACT FROM AUTHOR]

Wind controls the movement of water in large shallow lakes. It ultimately affects the water quality of large shallow lakes through sediment resuspension and nutrient diffusion. Impacts of the wind field, hence needed to be studied, especially; (1) the impacts of wind field on the vertical profile, and (2) on the generation of the reverse flow field at large shallow wind exposed lakes. The present study investigated the wind field impacts on the water flow field at different water depths in the large shallow Taihu Lake by using precise wind and velocity profile data acquired at Dongtaihu bay. The results revealed that wind speed and direction have dominant effects on water movement in the large shallow lake. High frequency of wind direction generates more frequent reverse flow field at each layer of the water column. The dominant wind directions found with a high probability of contribution in the generation of reverse flows at the surface (42.4%), upper middle (38.4%) and bottom (51.5%) layers with large-scale shear of the flow field. Similarly, probability statistics showed that dominant wind speeds have more contributions in the generation of compensation currents at the lower middle (42.6%) layer of the vertical water profile with medium scale shear of the flow field. High wind speeds play a major role in the generation of large flows at all layers of flow profile, but long-term steady wind speeds with consistent wind direction generate stable current in the large shallow lake which reduce the diffusion and nutrient resuspension in the large shallow Taihu Lake. Results of the current study provide a novel ground to study sediment/nutrient resuspension, transport and water quality scenarios in large shallow wind exposed lakes while considering reverse flow field in shallow waters. [ABSTRACT FROM AUTHOR]